National Republican Senatorial Committee Chairman Jerry Moran said Tuesday the GOP's pickup opportunities have expanded to around a dozen states — twice as many as needed to take control of the Senate.

"I think we have a good map in the sense that we have good candidates and good states," Moran told CQ Roll Call's Niels Lesniewski. "The map has expanded over time. In my view, [it] started out with six or seven — now 10 or 12." Republicans have clear advantages in South Dakota, West Virginia and Montana. About three months before the elections, the party is also in a better position in Iowa and Colorado than it was at the beginning of the year, and the GOP is giving Democratic incumbents strong challenges in states including Arkansas, Louisiana, North Carolina and Alaska.

Beyond that, Republicans are hopeful in Michigan, New Hampshire, Minnesota and a couple others, though Democrats remain favored in each of those.

"Again, all — all circumstances are positive for having good candidates in states that they can win," Moran said.

Of course, Republicans also have reasons to be concerned about their chances: Democrats are raising significant amounts of money, the GOP lacks a track record of defeating Democratic incumbents and the Republican brand is highly unpopular.

Democrats are also targeting the GOP-held seats in Kentucky and Georgia, though Republicans remain favored in both.

Click here to see the Rothenberg Political Report/Roll Call ratings map.